支持Modelica模型的半物理仿真系统设计及关键技术

针对当前基于MATLAB/SIMULINK的半物理仿真（Hardware in Loop Simulation,HILS）系统中不支持多领域建模、联合仿真模型转换过程复杂且存在误差等问题,提出基于Modelica和建模仿真软件MWorks进行HILS的方法,分析其所涉及的建模方法、实时仿真接口和代码生成等关键技术,并以此为基础构建支持Modelica模型的HILS.以前起落架转向系统和起落架收放系统为应用实例,建立HILS平台,对该方法进行验证.仿真结果表明该方法可行,结果可信度高.     

基于DDS的飞机机电系统组态监控技术研究

为了解决基于DDS的分布式协同仿真平台多节点、多模型条件下飞机机电系统复杂关联参数的实时监控问题,结合组态监控技术提出一种基于DDS的飞机机电系统协同仿真组态监控方法,设计了组态监控平台与分布式仿真平台的数据交互接口,实现飞机机电系统模型的实时过程监控以及监控界面的图形化显示;集成测试结果表明,该组态监控方法实现了对飞机机电系统复杂关联参数的读写、存储以及监控界面的图形化显示,提高了飞机机电系统的协同仿真验证效率,降低了分布式协同仿真监控系统的开发难度.     

基于实时网络的半物理仿真

复杂系统半物理仿真涉及的物理效应设备数量多、设备间通信量大,采用普通的串并口通信方式,连接复杂且可靠性差.该文针对此问题提出了一种基于实时网络的复杂系统半物理仿真实验方法,并以某型无人机飞控系统半物理仿真系统架构为例,验证了实时网络用于复杂系统半物理仿真实验的可行性.     

大型高空台进排气控制半物理仿真系统设计

为构建大型复杂高空模拟试车台进排气控制半物理仿真系统,提出了仿真模型和实物部件相结合的系统设计方法。依据系统结构组成及工作机理统筹规划系统仿真模型和实物部件,利用理论建模、系统辨识方法建立仿真模型,并基于PLC完成系统设计和软件开发,最终将仿真模型和实物部件高效统一形成半物理仿真试验台。通过仿真平台实现了系统一体化虚拟仿真,结果表明系统运行可靠稳定,能够准确模拟真实发动机试车过程。     

基于MapleSim的六自由度柔性机械臂动力学仿真

柔性机械臂是一个复杂的机电一体化系统,涉及到多个物理领域。传统柔性结构建模一直存在建模复杂、模型不易扩展、运行速度慢等缺点,而且难以实现多领域建模,忽略了不同物理领域相互作用给整体系统所造成的影响。为了提高建模效率和仿真准确度,采用MapleSim多领域建模仿真平台,建立了六自由度柔性机械臂模型,包括柔性臂杆、关节、伺服驱动系统、传感器等。基于模型,从多领域的角度研究了柔性机械臂的动力学特性。该方法建模工作量小,所建模型易修改。仿真结果表明了该方法的有效性。     

基于SysML的复杂机电系统设计模型形式化扩展与验证

形式化系统验证是保证系统设计正确性的一种重要手段.如何针对复杂机电系统物理与软件相融合的特征,对系统设计的动态特征进行验证,是系统验证研究领域亟待解决的问题.针对这一问题,对系统工程标准建模语言SysML进行扩展,提出了一套形式化系统模型验证方法.首先,以计算树逻辑和基于流的功能表示为形式化基础,形成基于SysML的系统功能建模方法;然后,以混合自动机为基础,建立基于SysML的系统行为建模方法;最后,针对物理与软件子系统的不同动态特征,借助NuSMV模型校验器,以层次化方式实现系统模型的自动验证.以移动机器人系统为例,展示了复杂机电系统设计模型的自动验证过程.     

特定领域建模与代码生成的研究与实现

DSM 通过提高抽象程度实现软件生产力的提高。本文在深入研究DSM 与元建模以及代码生成等技术后,提出一种特定领域建模与代码生成的方法,并建立起它的实现。本文归纳总结了创建特定领域元模型及其实现的方法与原则;介绍了使用GMF 通过特定领域元模型快速定制生成特定领域建模工具的过程;提出基于系统架构与框架创建覆盖不同业务类型的样例代码的方法与原则;总结归纳了特定领域建模与代码生成的整体过程;提出根据特定元模型将样例代码制作成代码模板的方法与原则;最后介绍了通用代码生成引擎的组成部分及其作用以及代码生成的过程。     

基于SysML和Modelica的复杂机电产品系统设计与仿真集成

系统仿真是辅助系统设计的一种重要手段,如何将系统设计与系统仿真有机结合,从而支持设计工作的高效开展,是一项重要的研究课题.针对这一问题,基于系统工程标准建模语言SysML和多领域仿真建模语言Modelica提出一套系统层设计与仿真集成方法.首先基于元对象机制分析和比较了SysML和Modelica的元模型;然后以Modelica元模型为基准,构造了面向Modelica的SysML扩展包M-Design;最后依据扩展的SysML和Modelica元模型定义了二者之间的映射规则,从而实现SysML设计模型向Modelica仿真模型的自动转换.以储水池系统为例,展示了复杂机电系统的设计和仿真的集成过程.     

基于组合式仪器平台和Simulink的半实物仿真系统研究

由于商业半实物仿真平台往往需要配合专用硬件使用,通用性较差、价格高昂,且国内半实物仿真平台较少,难以满足半实物仿真技术的学习教学需求。因此,本文设计实现了一种基于组合式仪器平台和Simulink的半实物仿真系统,通过分析RTW代码生成过程,实现Simulink模型的实时性扩展。并通过编写脚本文件,自动生成可在组合式仪器平台上运行的半实物仿真应用。实例运行表明,该半实物仿真平台具有较高的自动化程度和通用性。     

直升机通风加温控制系统半实物仿真平台开发

直升机机电系统往着信息与控制综合化的方向发展机电综合管理系统综合了越来越多的机电系统的控制功能。以往针对直升机机电综合管理系统控制功能的验证方法主要为系统间实物联试。实物联试周期长,测试范围有限且不能在设计早期暴露缺陷。针对上述问题,本文开发了机电系统半实物仿真平台,建立了机电系统模型仿真状态与机电接口测试台硬件接口之间的数据映射,实现了用机电系统仿真模型代替机电系统实物与机电综合管理系统进行联试。该试验平台可将机电综合管理系统控制功能验证提前至设计早期,并缩短了验证周期,提高了验证覆盖率。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.